Circuit breaker



June 20, 1939. J. a. MgcNElLL 2,163,558

C IRCUIT BREAKER Filed April 30, 1957 3 Sheets-Sheet 1 Insulationlmsulaiion WITNESSES: /30 I 37 I29 INVENTOR- WM John 5. Mac/Veil].

BY 2/ a Q ATTORNEY;

June 20, 1939. J, B MaCN'EM 2,163,558

7 CIRCUIT BREAKER Filed April 50, 19s? 5 Sheets-Sheet 2 f .5. F3" fig 4.WITNESSES: INVENTOR MM JO 5. Mac/Veil].

yaw/ Y BY Q I TTORNEY2 June 20, 1939.-

J. B. M QNEILL 2,163,558

CIRCUIT BREAKER Filed April 30, 1957 3 Sheets-Sheet 3 log //6 A67 I I 59//5 s 7/ it? -//9 l5 2r 5 -23 95 M 2 w /27 /2/ a a r .39 f1 75 Q; 77 165 i 57 47 P 5 I 4/ 2 I4 5 3 6/ 67 if 83 5/ 43 WITNESSES: INVENTOR MWJob/7 5. Mac A/ez'ii,

and are extinguishing liquid.

" space and requires a very large quantity of oil i aienteci June 2G,

UITD

creeper BREAKER 301m B. MacNeiii, Wilkinsburg, Pa., assignor toWestinghouse Electric & Manufacturing Company, Ea-st Pittsburgh,'Pa., acorpcraticn of Pennsyivama Application April 3t), 1937, Serial No.139,921

The invention relates to switchgear apparatus in general and moreparticularly to circuit breakers for controlling high voltagetransmission systems.

It has heretofore been the usual practice, in the case of large capacitycircuit breakers, to enclose the relatively movable contacts and otherrelated parts in a metal tank. Large insulator bushings were necessaryto insulate the terminals of the breaker from the metal tank; and thetank itself had to be of large dimensions in order to provide sufficientspace between the tank and all of the live parts. In high capacitybreakers of this type, the metal tank occupies considerable the seriesof tandem arranged pairs of contacts of the breaker which providesmaximum travel and speed of operation of the switch member together withhigh contact pressure when the breaker is closed.

Another object of the invention is the provision of a circuit breaker aspreviously described in which the contact assemblage is secured to a capmember which is removably mounted in the casing; the improved actuatingmeans being supported by the cap member so that the entire assemblagetogether with the actuating means may be readily removed with the capmember from the casing for inspection, repairs or re placements.

Another object of the invention is the provision of an improved oilcircuit breaker embodying a pair of contact assemblages each including aseries of tandem arranged interconnected circuit controlling arcextinguishing units mounted in the upper sections of a pair of hollowcylindrical insulator columns and connected by a series connectorbridged between the two columns, the arrangement of the current paththrough the breaker being such as to provide more nearly equal voltagedistribution between the several units, and in many cases eliminatingthe necessity of providing separate condenser shielding means for thispurpose.

Another object of the invention is the provision of an improved circuitbreaker, as previously described, in which the lower sections of theinsulator columns provide space for current transformers and potentialdividers thus eliminating the necessity of separate containers andinsulator bushings for these devices.

Another object of the invention is the provision of a circuit breakerembodying a casing of strong insulating material for enclosing andsupporting a contact assemblage including at least one pair ofrelatively movable contacts and actuating means therefor, and an outerweatherproof housing of vitreous insulating material surrounding andprotecting said casing; so that in the event of breakage of the outerhousing the circuit breaker remains completely operative.

In carrying out the invention, two hollow cylindrical columns ofvitreous insulating material replace the metal tank formerly used. Thelower portions of the columns serve to elevate and insulate the liveparts from ground and to provide containers for current transformers andpotential dividers to be used for relaying and indicating purposes. Theupper portion of each column forms an interrupting section which conforinsulation purposes. The large amount of oil required constitutes adangerous fire hazard due to the fact that it may be ignited on shortcircuit or on surges due to lightning flashes or other causes.

It has been proposed to use casings of vitreous insulating material inplace of the metal tank in order to reduce the space occupied and theamount of oil required by the breaker. Such an arrangement is usuallyreferred to as a porcelain clad oil-poor circuit breaker. Circuitbreakers of this type are of more or less recent develop ment and muchis yet to be desired in the way of a satisfactory structure. The presentinvention relates to circuit breakers of this type and one object of theinvention is the provision of an improved porcelain clad circuit breakercapable of controlling and interrupting extremely large amounts ofelectric power, which is simple, safe and reliable in operation andrelatively inexpensive to manufacture and service.

Another object of the invention is the provision of an improved circuitbreaker in which the contact means, actuating means and other relatedparts are disposed in tubular insulating casings of. relatively smalldiameter so that the breaker occupies a relatively small amount. ofspace and requires a small quantity of insulating Another object of theinvention is the provision of a circuit breaker having a unitary contactassemblage including a plurality of pairs of relatively movable maincontacts and associated arc extinguishing means and a pair of auxiliaryseparable disconnecting contacts, connected in series and arranged intandem within a small diameter tubular casing of insulating material foroperation by an improved high speed actuating means.

Another object of the invention is the provision of an improvedactuating means for operating tains a unitary removable contactassemblage comprising a plurality of interconnected circuit controllingarc extinguishing units arranged in tandem, the relatively movablecontacts of which are connected in series. The series of connected arcextinguishing units are connected with line terminals 10 ated at thebase of the interrupting sections an with a series connector bridgedbetween the top of the two columns.

The novel features that are considered characteristic of the inventionare set forth in particular in the appended claims. The inventionitself, however, both as to structure and operation, together withadditional objects and advantages thereof will best be understood fromthe following detailed description of one embodiment thereof when readin connection with the accompanying drawings, in which Figure l is afront elevational view of an arrangement for mounting a plurality ofsingle pole circuit breaker units constructed in accordance with thepresent invention, for gang operation to form a multi-pole breakerassembly.

Fig. 2 is an enlarged side elevational view, partly in section of one ofthe individual single pole circuit breaker units embodying the featuresof the invention;

Fig. 3 is an enlarged elevational view partly in section of a portion ofone of the unitary contact assemblages;

Fig. 4 is a view similar to Fig. 3 taken at right angles thereto showingthe parts of the contact assemblage in the closed-circuit position ofthe breaker;

Fig. 5 is a view similar to Fig. 4 showing the parts of the contactassemblage in the open-circuit position of the breaker; and,

Fig. 6 is an enlarged elevational view, partly in section of aninterrupting section of the circuit breaker.

Referring to the drawings, and particularly to Fig. 2 thereof, thesingle pole circuit breaker unit illustrated is provided, with asupporting base I of the truck type having a pair of rollers 9 at eachend thereof to facilitate moving the breaker unit into and out ofposition. A pair of vertically arranged hollow columns II and I3 ofvitreous insulating material, such as porcelain or the like, are mountedin spaced relation on the base 1, one adjacent each end thereof. Thecolumns may consist of a single piece of vitreous insulating material orthey may be made up of several sections I5, I! and I9 secured end toend, as shown in Fig. 2. The several sections are clamped together andthe whole column clamped to the base I, in any suitable mannenpreferablyin such a manner that only compressive stresses are applied to thecolumns.

A tube 2| of insulating material compounded from fibrous materialimpregna ed with synthetic resin extends concentrically through thelower sections l1 and IQ of eachcolumn, while a similar tube 23, also ofsimilar insulating material, extends concentrically through the uppersection l5 of the column. 1

A ring member 25 providedwith an internal flange 21 (Fig. 6) is rigidlysecured to the upper end of each of the inner insulating tubes 23. Eachof the ring members 25 has a second internalfiange 29 which abutstheupper end of the outer porcelain section l5 of the column.

A unitary contact assemblage, indicated generally at 3|, is removablymounted in the upper section l5 of each insulator column. The unitarycontact assemblage comprises, in general.

a stack of individual circuit making and breaking units 33 arranged intandem relation, a movable switch member 35 (Figs. 3 and 4), and anactuating means indicated generally at 31 for the switch member andstack of circuit making and breaking units.

Referring to Figs. 3, 4 and 5, each circuit making and breaking unit 33comprises, in general,

a stationary contact 39, a cooperating movable contact 4| and anassociated arc extinguishing means for the contact indicated generallyat 43. Any suitable type of arc extinguishing means may be used. Onepreferred form of arc extinguishing means that may be used is shown anddescribed in detail in the co-pending application of Howard M. Wilcox,Serial No. 83,597, filed June 5, 1936, issued October 12, 1937, asPatent No. 2,095,301 and assigned to the assignee of this invention.Another suitable form of arc extinguishing means that may be used isshown and described in detail in the copending application of Roswell C.Van Sickle, Serial No. 83,600, filed June 5, 1936, also assigned to theassignee of this invention. Each unit 33 has a pair of end plates 45 anda cylindrical shell of insulating material 41.

The several circuit making and breaking units 33 are secured together inspaced stacked relation by means of tie brackets 49, and the pairs ofcontacts of the several units which will hereinafter be referred to asthe main contacts, are connected in series circuit relationship so thatduring a circuit opening operation, theare formed incident to theopening of the circuit plays as a series of arcs, which are quicklyextinguished by the arc extinguishing means 43 of the several units.

The movable contacts 4| of the several circuit making and breaking units33 are adapted to be simultaneously actuated by means of a commoninsulating rod 5| which extends centrally through all of the units, themovable contact 4| of each unit being connected to the rod by means of apair of levers 53. The levers 53 are pivoted at their one end to fixedbrackets 55 secured to the top plate of each unit, the free ends of thelevers being connected to the movable contact 4| by.

means of a pivot pin5'l. The intermediate portions of each of the levers53 is connected to the common actuating rod 5| by means of a pivot pin59. The levers '53 are each provided with a slot .(not shown) forengaging their fixed pivot pin 6| carried by the brackets 55 in order topermit straight line motion of the common actuating rod 5| and thecontacts 4|. The common actuating rod 5| is biased in an upwarddirection by means of a suitable compression spring (not shown) so thatthe movable contacts 4| of the several units 33 are all biased to theiropen circuit position.

' The upper end of the rod 5! has a frictionally engageable femalecontact 63 secured thereto for cooperation with a movable male contact65 secured to the lower end of the switch member 35. Any type of springbiased female contact may be used which will resiliently andfrictionally grip the cooperating male contact 65. The contact 63 inthe-actual physical embodiment of the invention has a plurality ofcircularly arranged fingers (not shown) which are biased inwardly by acoil spring means (not shown) so that they will firmly grip thecooperating male contact 65. The con tacts 63 and 65 form what will bereferred to as a pair of separable auxiliary disconnecting contacts. Thecontact 63 is connected by a suitable shunt conductor (not shown )and bythe levers 53 and pins 51 and 59 with the movable contact of theuppermost circuit making and breaking unit 33. A second frictionallyengageable female contact 61 (Fig. 6) similar to the contact 83 issecured to the bottom plate of the lowermost circuit making and breakingunit 33, and this contact is electrically connected to the stationarycontact 39 of said lowermost unit. The contact member 61 serves toconnect the units 33 of the stack in circuit with a line terminal in amanner which will be hereinafter described.

The shell 41 of the uppermost circuit making and breaking unit 33 issecured to the lower end of a sleeve 89 of molded insulating material,the upper end of the sleeve being, in turn, secured to a spider casting.or cap member II. The cap member 1| is provided with a pair ofoppositely extending integral projections I3 which are adapted to seaton the internal flange 2I of'the ring member 25. Suitable bolt fasteningmeans pass through openings provided in the projections 13 and throughsimilar aligned openings provided in the internal flange 21 for securingthe cap member II in mounted position within the sleeve 25 so that theentire unitary contact assemblage 3| is removably mounted within theinsulating tube 23, the stack of circuit making and breaking units beingdisposed within said, insulating 'tube.

The switch member 35 comprises a metallic yoke which is mounted forvertical sliding movement in the insulating sleeve 89 which connects thecap member II with the stack of circuit making and breaking units 33.The yoke member 35 is mounted for vertical sliding movement betweenpairs of guides 15 which are secured by means of rivets 11 to the innersurface of the sleeve 89. The yoke 35 is provided with four rollers I9which are adapted to roll in. grooves provided between the pairs ofguides I5. The yoke member 35 with the movable contact 85 secured to thelower end thereof is movable between an open and a closed circuitposition to open and close the circuit through the breaker. The closedcircuit position of the yoke member is shown in Figs. 3 and 4, and theopen circuit position thereof shown in Fig. 5.

It will be seen from the structure thus far described that when the yokemember moves from its closed-circuit position to its open-circuitposition, the insulated actuating rod 5| is moved upwardly under theinfluence of its biasing spring (not shown) to efiect simultaneousopening of each pair of maincontacts of the several interrupting units.When the movable contacts 4| have reached their full open circuitposition, upward movement of the insulating rod 5| ceases. The continuedupward movement of the yoke 35 to its open circuit position causes themovable contact to separate from the cooperating stationary contactmember 83. The movable contact 65 moves upwardly with the yoke 35 asuflicient distance to introduce a large gap between the contacts 63 and85 capable of withstanding high voltages. The contacts 83 and 85 thusact in the manner of a disconnecting switch to protect the circuitmaking and breaking units 33 from surges due to lightning flashes andother causes in the open circuit position of the breaker.

When the movable yoke 35 is moved from the open-circuit position shownin Fig. 5 to the closedtact 65 is first brought into frictional engage-vment with its cooperating stationary contact by means of suitable cotterpins.

member 63 carried by the upper end of the insulated actuating rod 5|,thus closing the auxiliary disconnecting contacts. Further, downwardmovement of the yoke member 35 efiects downward movement of theactuating rod 5| against the force exerted by its biasing spring tocause simultaneous closing of all of the main contacts of the severalcircuit making and breaking units. During a circuit opening operation, aseries of short arcs are formed which are quickly and completelyextinguished within the several circuit making and breaking units 33before the contacts 63' and 65 separate so that no arcing takes placebetween these last-mentioned contacts.

A'spider ring 8| (Fig. 2) is mounted between the lower end of theinterrupting section I5 and the upper end of the section I! of each ofthe hollow insulating columns. The spider ring 8| carries a centrallylocated conducting stud 83 (F;g. 6) which is adapted to be frictionallyengaged by the contact member 61 of the lowermost circuit making andbreaking unit 33, as shown in Fig. 6. The contact stud 83 iselectrically connected with a line terminal connector carried by thespider 8| which extends outside of the insulating column and whichserves to connect the breaker in an external circuit. The line terminalconnection 85 is insulated from the spider ring 8| by means of aninsulating bushing 81. The contact 61 and the conducting stud 83 form aseparable electrical connection between the stack of circuit making andbreaking units 33 and the line terminal connection 85, which permits theunitary contact assemblies 3| to be readily removed from the insulatingtube 23 without necessitating the disconnection of any circuitconductors.

A high speed actuating means indicated generally at 31, Figs. 3, 4 and5, for the movable switch member 35 is disposed within the cap member'II and the sleeve 89. The actuating means comprises in general a pairof main driving levers 89, an intermediate multiplying lever 9| and apair of floating levers 93. The main driving levers 89 are pivotallymounted at their one end on a shaft carried by the cap member 1|. Thedriving levers 89 are connected by a bridging member 96 for simultaneousmovement together. The intermediate multiplying lever consists of a yokeshaped member pivoted at one end to a pairof studs 99 formed integralwith the cap member 'II. Links I 0| pivotally connect the outer freeends of the driving levers 89 with a transverse pivot pin I03 bridgedbetween the legs of the intermediate lever 9|. The ends of the links IOIengage the transverse pivot pin I03 while the other ends thereof areprovided with pivot studs 91 which engage openings provided in the outerends of the levers 89. The free ends of the legs of the yoke 9| areoflset outwardly and are connected to the central portions of thefloating levers 93 by means of pivot studs I05, the pivot studs I05being formed integral with the floating levers 93 and extending throughopenings provided in the ends of the legs of the intermediate yokeshaped lever 9| and retained in mounted position thereon The ends I01 ofthe floating levers 93 are pivotally connected to the upper ends of thelegs of the movable yoke member 35 by means of pivot pins I09, as bestshown in Fig. 3.

The intermediate yoke shaped lever 9| is biased in a counter-clockwisedirection about its pivot studs 99 by means of a pair of oflset leversIII which are pivotally mounted on the studs 99. The offset portions H3of the levers III are adapted to engage shoulders formed on the legs ofthe yoke shaped lever 9|. A pair of coiled compressing springs II5 serveto bias the levers III in a counter-clockwise direction, the forceexerted on the levers III being transmitted through the shoulders of thelegs of the yoke shaped lever 9| to bias the same in a counter-clockwisedirection about its pivot studs 99 to the open circuit position shown inFig. 5.

The position of the various levers of the actuating mechanism when thebreaker is closed are illustrated in Fig. 4. It will be noted that inthe closed-circuit position, the lower portion of the floating levers93, that is to say, that portion from the pivot studs I05 to the pivotpins I09, together with the lower angular portion of the intermediatelever 9|, that portion between the transverse pivot pin I03 and thepivot studs I05 form a. toggle which is in the made position. Thistoggle in the closed-circuit position of the breaker maintains a highcontact pressure between the cooperating contacts of the contactassemblage. In order to break the previously mentioned toggle at thebeginning of the circuit opening operation, the intermediate yoke shapedlever 9| is provided with a pair of projections III on the oppositesides thereof which are operable at the beginningof the circuit openingoperation to thrust the free ends of the floating levers 93 to theright, as viewed in Fig. 4, thus breaking the aforementioned toggle. Thecap member II is provided with a pair of recesses H9 for receiving pivotstuds |20 carried by the free ends of the floating levers 93, during aportion of the movement of said levers, the recesses I I9 serve toprovide temporary pivot bearin s for the studs I20 and the free ends ofthe levers 93 during certain portions of the movement of the levers.They also permit the levers 93 to 'move longitudinally in a horizontaldirection during portions of the circuit opening and closing operationso that the pivot pins I09 may travel in a vertical line. The variouslevers of the actuating mechanism thus form a straight line levermechanism for actuating the switch member 35. The predeterminedarrangement of the levers also provides a multiplying action, whichmultiplies both the travel and the speed of the operation of the switchmember over that of the main driving levers 09, as can readily be seenfrom a comparison of Figs. 4 and 5. The switch member 35 and the movablecontact 65 carried thereby travel a considerable distance in a verticaldirection whereas the main levers 89 move through a relatively small arcto effect such movement of the switch member 35 and contact 65.

The operation of the actuating mechanism is briefly as follows: With theparts of the actuating mechanism in the position shown in Fig. 4 and allof the pairs of contacts closed, let it be assumed that it is desired toopen the contacts. The main driving levers are rotated from the positionshown in Fig. 4 in. a counter-clockwise direction about their shaft 95to the open-circuit effect counter-clockwise rotation of said leverabout the pivot studs 99. During the initial portion of thecounter-clockwise movement of the yoke shaped lever 9|, the projectionsIII thereof engage and move the upper free ends of the floating levers93 toward the right to break the toggle formed by the lower ends of thelever 9| and the lower portions of the floating levers 93. The drivinglevers 89 and the intermediate yoke shaped lever 9| both move in acounter-clockwise direction about their fixed pivot axes, theintermediate lever 9| moving at a greater speed due to the fact that thefree ends of the levers 89 are pivotally coupled to the transverse pivotpin I03 of the yoke shaped lever 9| which is located a considerabledistance from the pivot axis 99 of the intermediate lever. During thecounter-clockwise movement of the lever 9|, the floating levers 93 aremoved both longitudinally and rotatably about their pivot axes I05 fromthe position shown in Fig. 4 to the position shown in Fig. 5,

to effect movement of the yoke-shapedswitch' member 35 from its closedto its open circuit position. The movement of the yoke shaped member 35from closed to open position eifects simultaneous opening of all of thepairs of main contacts 39 and 4| and the auxiliary contacts 63 and 65 inthe manner previously described. During the latter part of the circuitopening operation, the studs I20 on the free ends of the floating levers93 move into the recesses H9 provided to accommodate the same.

During a circuit-closing operation, substantially the reverse action ofthe actuating mechanism takes place. The driving levers 89 are rotatedfrom the position shown in Fig. 5 in a clockwise direction about theirpivot axes to the closed position shown in Fig. 4. Since the free endsof the driving levers 89 are pivotally coupled to the transverse pin I03of the intermediate lever 9|, the lever 9| is also rotated in aclockwise direction about its pivot axis 99 from the position shown inFig. 5 to the position shown in Fig. 4, with a greater speed and alonger are however than that of the levers 89. The clockwise movement ofthe intermediate yoke shaped lever 9| moves the pivot pins I09 from theposition shown in Fig. 5 to the position shown in Fig. 4 to effectrotation and bodily movement of the floating levers 93 from the positionshown in Fig. 5 to that shown in Fig. 4. This movement of the floatinglevers drives the switch member 35 from its open-circuit position to itsclosed-circuit position to effect closing of all of the pairs ofcontacts in the manner previously described. During the initial portionof the movement of the floating levers to their closed-circuit position,the recesses I I9 act as a temporary pivot bearing for the studs I20 sothat considerable force is transmitted through the lever mechanism and ahigh speed closing operation takes place. During the latter part of themovement of the floating levers 93 to their closed circuit position, thetoggle formed by the lower portions of the intermediate yoke shapedlever- 9| and the floating levers 93 moves into fmade position, as shownin Fig. 4, to secure a high contact pressure between the cooperatingcontacts of the contact assemblage. The novel arrangement of the variouslevers of the actuating mechanism provide for a multiplied speed andtravel of the switch member 35 over that of the driving levers 89 tosecure a maximum travel and speed of operation of the switch memberobtainable within the limited diameter of the tubular insulating member23 and the porcelain. column.

arouses An adjustable stop member HE? is threaded through the top oi thecap member for limit ing counter-clockwise movement of the iuter mediateyoke shaped lever The stop rosin ber 2'32 may be adjusted to vary theamount of upward travel oi the switch member 35 and hence the length oithe gap between the contact '55 and the contact breaker. Adjustingscrews lit are also provided in the cap member ii for changing thetension or force exerted by the biasing springs i it which tend to openthe breaker.

The actuating mechanism in each coltuon of the circuit breaker isoperable from outside or" columns means of a pair of interconnected.insulating rods and (Fig. 2) the rods being interconnected by amultiplying lever disposed and pivotally mounted the spider ring memberti. lhe upper end of the rod illl is pivotally connected to a transversepin it?! bridged between the driving levers and located adjacent thepivot shaft of said levers. The lower ends of the insulating rods itsextend through the bases of the insulating columns and are pivotallyconnected to the ends of hell crank levers 29. A tube of insulatingmaterial 326 surrounds each rod W3 and is joined at respective ends tothe upper and lower closure members lit and it!) as shown in Fig. 2, soas to prevent the interchange of insulating liquid between thetransformer compartment in sections ii and i9 and the interruptingcompartment in section it of the column 5 l.

Provision is made for simultaneously driving the rods and Hill in eachcolumn to effect simultaneous operation of the contact means of thecontact assemblages in each of the twocolumns. Any suitable means may beprovided for this purpose. in Fig. 2, a means is shown which comprises aT-shaped lever iii pivotally mounted by means or" a pin 333 on the basei, the outer ends of the T portion being pivotally connected to the bellcrank levers 5253 by means of links i335. the end of the stem of theT-shaped lever iill being pivotally connected to an operating rod till.The operating rod till may be con nected to any suitable typeofoperating mecha nism either of the motor driven or solenoid operatedtype and by which the operating rod lt'l is biased in a direction toopen the breaker and is held in closed-circuit position by a suitablelatching mechanism releasable by a trip means. The driving motor orsolenoid provides a driving force for moving the operating rod to effecta circuit closing operation of the breaker.

The tubular casing its is bridged between the cap members at the top ofthe two columns i! and it. The contact means of the two unitary contactassemblages 3! which are mounted in the two columns are connected inseries circuit by means of a conductor which extends through the tubularbridging member its. This conductor (not shown) is connected to asuitable flexible shunt conductor Ml carried by each of the con tactassemblages 38, the lower end M3 of the flexible shunt conductor Mibeing electrically connected to the contact or" the switch member 35.

The circuit through the breaker extends from the left hand line terminalconnection 35 of the column ll through the conducting stud B3 and thestack of circuit making and breaking units 33, through the separablecontacts and S5, flexible shunt conductor Mi through the corn ductorhoused within the tubular bridging memsemblage mounted in the column inthe open position of the her and a conductor Ml of. the contact asitl,through the disconnecting contacts 53 and and the stack of circuitmaking and breaking units 33 housed in said column 53 to the right handterminal connection Disposed within the lower sections El and is of thecolumn ii are the windings of a current transformer M5. The currenttransformer is of the type which has its primary terminals at one end atline potential and its secondary terminals at the other end at groundpotential. The primary winding is connected in series in the circuitbetween the conducting stud 815 and the line terminal transformer may beconnected by its terminals to suitable relays and indicating instrumentsas esired.

A potential transformer or voltage divider it! is mounted within thelower sections it and it of the insulator column 93. The transformer Mlcomprises a plurality of primary and secondary coil units hill, theprimary coils of the units being connected between the line terminalconnection 85 and ground. The secondary voltage taken from the secondarycoils may be used for relaying or voltage measuring purposes.

The arrangement of the current transformer and the potential transformerwithin the lower sections of the insulating columns is most advantageousin that it reduces the space occupied by the breaker, requires much lessinsulation thanwas formerly used and eliminates the necessity of.separate containers or tanks; together with the necessary insulatingbushings therefor.

The'arrangement of the current path through the circuit breaker in whichthe line terminal connections are positioned above, and insulated fromground by the lower sections of the insulating columns. together withthe series connector between the tops of the two columns which connectsthe contact means in each column in series, is an important feature ofthe invention, This arrangement of the current path provides a moreequal distribution of the voltages between the serics of contacts andthe associated metallic parts to which the contacts are connected, ineach column so that the burden of extinguishing the arc during circuitinterruption is divided substantially equally between the circuitinterrupting devices 33 or" the two contact assemblages.

With the circuit path arranged as illustrated the capacitance of theseries connector H5 with respect to ground is relatively small due tothe fact that the series connector is at a greater The secondary coil ofthe current distance from ground than are the terminals of the breaker.Assuming that a ground occurs in the load circuit, which is the worstcondition obtainable, the capacitance of the series connector, 939 toground is in parallel with the series of contacts in column it on theload side of the breaker. If the capacitance of. the series connector539 to ground were zero, the voltage distribution between the two seriesof contacts in the two columns would be equal. Since this capacitance ofthe series connector to ground is relatively small as stated above, thevoltage distribution between the two series of contacts will besubstantially equal.

if the terminals 85 of the breaker were arranged at the top of the uppercolumns is, and the series connector 532 at the'oottom of the twocolumns, the capacitance oi the series conhector 539 to ground would begreater than in the arrangement of the present invention. With internalflange of the ring members 25.

spe'ction, repair or replacement purposes.

large resulting capacitance to ground would be.

in parallel with the series of contacts in the column on the load sideof the breaker. With this arrangement an unequal distribution of thevoltage between the two series of contacts in the two columns is wouldresult.

The upper sections i5 of each column are filled with an insulating arcextinguishing liquid. to a level above the auxiliary disconnectingcontacts 6365. The-spider rings 85 are provided with any suitablesealing means so that the upper sections iii are made oil tight. Thelower sections H and IQ of. each column are also filled with aninsulating liquid kept .separate from the liquid in. the upper sectionsby the aforementioned sealing means. Since thecolumns are of relativelysmall diameter, just suificient to house the unitary contact assemblageswith their stacks of circuit making and breaking units, much lessinsulating liquid is required than in the case of metal clad circuitbreakers.

The upper ends of the ring members 25 are closed by suitableclosure'members i5! which are removably mounted on' the ring members.The feature of removably mounting the unitary contact assemblages withinthe interrupting sections i5 of the two columns is most advantageous inthat it facilitates the servicing of the breaker. To remove the contactassemblages, it is only necessary to remove the closure members $58 andthe bolts which secure the cap members ii to the The contact assemblagesmay then be withdrawn from the tubular insulating members 23 for in- Theseparable connection between the stack of circuit making andbreaking'units 33 and the line terminal connectors 855 permits removalof the contact assemblages without disconnecting any con ductors.

' It is believed that the operation of the circuit breaker will bereadily understood from the preceding description. To close thecircuitbreaker, the operating rods H23 and E2! in each column are movedsimultaneously in a downward direction by the operating mechanism toefiect movement of the pairs of. driving levers 89 of the actuatingmechanisms fromopen to closed circuit position to efiect simultaneousoperation of the contact means in both columns in the manner previouslydescribed. The operating rod 03! is held in closed-circuit position bymeans of the latch mechanism of the operating means. When the latchmechanism is caused to release the operating rod it? by the trip meansor the operating mechanism; the biasing springs of the operatingmechanism acting on said rod effects sigreases which carries the movablecontact 5 to provide a large gap capable of withstanding extremely highvoltages to protect the circuit making and breaking devices from surgesdue to lightning flashes and other causes when the breaker is in theopen position. i

Fig. 1 illustrates a plurality of the pole units previously describedmounted on a supporting frame I52 in spaced relation to form a 3 polebreakerassembly. The operating rods till, of the pole units areconnected to a suitable lever mechanism indicated generally at PS3 forsimultaneous operation thereby so that all of the pole units are adaptedfor simultaneous actuation to open and close the circuits through thebreaker.

It will be noted that in the event of breakage of any portion of theouter porcelain columns the breaker still remains operative because ofthe inner tubular insulating member which serves to support the unitarycontact assemblage and retain the insulating liquid for the same. Theseinner tubular members are capable of withstanding weather conditions fora limited period of time, at least until the outer tubular columns have.been repaired or replaced after be given the broadest reasonableconstruction in the light of the prior art.

I claim as my invention:

1. In a circuit breaker for high voltage power circuits, a substantiallytubular casing of insulating material, .a switch member movable to openor to closed-circuit position to open or to close the circuit throughthe breaker, means mounting: said switch member for movement.

withinsaid casing in the directionof ,the longitudinal axis thereof,actuating means disposed in said casing for moving said switch member toopen or to closed-circuit position comprising a. main driving leverpivotally supported adjacent one end, an intermediate multiplying leverpivotally supported adjacent one end, the free end of said main leverbeing pivotally coupled to said intermediate lever adjacent the pivotend thereof, a translatable lever pivoted intermediate its ends to thefree end of said intermediate lever, one end of said translatable leverbeing pivotally connected to said switch member. v

2. In a circuit breaker for high voltage power circuits, a substantiallytubular casing of insu-. lat-ing material, a switch member movable toopen or to closed-circuit position to open or to close the circuitthrough the breaker, means mounting said switch member for movementwithin said casing in the direction of the longitudinal axis thereof,-actuating. means disposed in said casing for moving said switch memberto open or to closed-circuit position comprising a. main driving leverpivotally supported adjacent one end, an intermediate multiplying leverpivotally supportedadjacent one end, the free end of said main leverbeing pivotally coupled to said intermediate lever adjacent the pivotend thereof, a third lever pivoted intermediate its ends to the free endof said intermediate lever, one end of said third lever being pivotallyconnected to said switch member and its other end being free, saidactuating means providing for maximum travel and speed of operation oisaid switch member aicasce nited diameter of said in said casing formoving said switch member to open or to closed circuit positioncomprising a main driving lever pivotally supported adjacent one end, anintermediate multiplying lever pivotally supported adjacent one end, thefree end of said main lever being pivotally coupled'tc said intermediatelever adjacent the pivot end thereof, a translatable lever pivotedintermediate its ends to the free end of said intermediate lever, oneend of said translatable lever being pivota y connected to said switchmember and other end being free, guide means for the free end of saidtranslatable lever; an operating rod extending into said casing andconnected to said main driving lever for operating the same, saidactuating means multiplying the travel and speed of operation of saidswitch member over that of said operating rod.

i. In a circuit breaker for high voltage power circuits, a substantiallytubular casing of insulating material, contact means mounted in saidcasing including at least one pair of relatively movable contacts, aswitch member movable to open or to closed-circuit position to open orclose said contacts, means mounting said switch memher for movement inthe casing in a path substantiallyparallel to the longitudinal axisthereof,- actuating means disposed in said casing for moving said switchmember to open and to closed-circuit position comprising a levermechanism including a translatable lever pivotally connected to saidswitch member, a guide for said lever; an operating rod extending intosaid casing for operatirig said lever mechanism, said contact means,switch member, and actuating means forming a unitary assemblage andmeans for removably mounting saidassemblage in said casing.

5. In a circuit breaker for high voltage power circuits, a substantiallytubular casing or insulating material; a unitary contact assemblagemounted in said casing including a plurality of pairs of relativelymovable main contacts and associated arc extinguishing means, a pair ofauxiliary separable contacts, the contacts being arranged in tandem andconnected in series, a switch member movable substantially parallel tothe longitudinal axis of the casing to open and to closed-circuitposition to open and to close all of said pairs of contacts, said switchmember being operable during a circuit opening operation to first effectsimultaneous opening of all of said pairs of main contacts and tosubsequently separate said auxiliary contacts a sufiicient distance tointroduce a large gap capable of withstanding high voltages, andoperable during a circuit clos" ing operation to first close saidauxiliary contacts and subsequently effect simultaneous clos ing of allof said pairs of main contact-s, and an actuating means for moving saidswitch member to open or to closed-circuit position comprising astraight line lever mechanism including a floating lever pivotallyconnected at one end to said switch member; an operating rod extendinginto said casing for connection with said lever mechanisin to actuatethe same, said lever mechanism multiplying the travel speed of operationof said switch memberover that of said operating rod.

6. in a circuit breaker for high. voltage power circuits, asubstantially tubular casing of insulating material, a unitary contactassemblage mounted in said casing including a plurality of pairs ofrelatively movable main contacts associated arc extinguishing means,apair of auxiliary separable contacts, the contacts being arranged intandem and connected in series, a switch member movable substantiallyparallel to the longitudinal o the casing open and to closed-circiutposition to open and to close all of said pairs of contacts, said switchmember being operable during a circuit-opening operation to effectsimultaneous opening of of said pairs of main contacts and tosubsequently separate said auxiliary contacts a sufficient clis-= tanceto introduce a gap capable of withe standing high voltages, and operableduring a circuit closing operation first close said iliary contacts andsubsequently efiect simultaneous closing of all of said pairs or maincon tacts, and an actuating means for moving said switch member to openor to closed circuit position comprising a straight line lever mechanismincluding a floating lever pivotally con nected at one end to saidswitch member; an operating rod extending into said casing forconnection with said lever mechanism to actuate the same, said. levermechanism multiplying the travel and speed of operation of said switchmember over that of said operating rod, said unitary contact assemblageincluding said contacts, said arc extinguishing means, said switchmember and said actuating means, being removably mounted in said casing.

7. In a circuit breaker for high voltage power circuits, a substantiallytubular casing of insulating material, a contact assemblage mounted insaid casing including a plurality of pairs of relatively movable maincontacts and associated arc extinguishing means, a pair of auxiliaryseparable contacts, the contacts being arranged in tandem and connectedin series, a switch member movable substantially parallel to thelongitudinal axis of the casing to open and to closed-circuit positionto open and to close all of said pairs of contacts, said switch memberbeing operable during a circuit opening operation to first efiectsimultaneom opening of all of said pairs of main contacts and tosubsequently sepa' 'rate said auxiliary contacts a sufiicient distanceto introduce a large gap capable of withstanding high voltages andoperable during a circuit closing operation to first close saidauxiliary contacts and subsequently effect simultaneous closing of allof said pai s of main contacts, and an actuating means for moving saidswitch member to open or to closed-circuit position comprising astraight line lever mechanism including a floating lever pivotallyconnected at one end to said switch member; an operating rod extendinginto said casing for connection with said lever mechanism to actuate thesame, said lever mechanism multiplying the travel and speed of operationof said switch member over that of said operating rod, said casing beingof limited diameter just sufficient to receive said contacts and arcextinguishing means, said lever mechanism securing maximum travel-andspeed of operation of said switch member obtainable within the limiteddiameter of saidcasing.

8. in a circuitbreaker for high voltage power circuits, a tubular casingof insulating material, a unitary contact assemblage disposed in saidcasing including a stack of circuit interrupting units each including apair of relatively movable arcing contacts, an operating memberconnected to said contacts for simultaneously opening and closing all'of said pairs of contacts, means biasing said operating member to opensaid contacts, an auxiliary contact carried by said operating memberadjacent one end, means connecting said auxiliary contact and saidarcing contacts in series, a switch member movable in a directionparallel to the longitudinal axis of the casing to open and toclosed-circuit position to open and to close the circuit through thebreaker, said switch member being operable during a circuit closingoperation to first engage said auxiliary contact and subsequently movesaid operating member to simultaneously close said arcing contacts, andoperable during a circuit opening operation to first move away from saidstack to permit said operating member to simultaneously open all of saidpairs of arcing contacts, and subsequently separate from said auxiliarycontact to introduce a large gap capable of withstanding high voltages,actuating means for moving said switch member to open and toclosedcircuit position comprising a main driving lever, a floating leverpivotally connected to said switch member and means connecting saiddriving lever to said floating lever for multiplying the travel andspeed of operation of said switch member over that of said main drivinglever and for maintaining a high contact pressure between said contactswhen the breaker is closed.

9. In a circuit breaker for high voltage power circuits, a tubularcasing of insulating material, a unitary contact assemblage disposed insaid casing including a stack of circuit interrupting units eachincluding a pair of relatively movable arcing contacts, an operatingmember connected to said contacts for simultaneously opening and closingall of said pairs of contacts, means biasing saidoperating member toopen said contacts, an auxiliary contact carried by said operatingmember adjacent one end, means connecting said auxiliary contact andsaid arcing contacts in series, a switch member movable in a directionparallel to the longitudinal axis of the casing to open and toclosed-circuit position to open and to close the circuit through thebreaker, said switch member being operable during a circuit closingoperation to first engage said auxiliary contact and subsequently movesaid operating member to simultaneously close said arcing contacts, and1 operable during a circuit opening operation to first move away fromsaid stack to permit said operating member to simultaneously open all ofsaid pairs of arcing contacts, and subsequently separate from saidauxiliary contact to introduce a large gap capable of withstanding highvoltages, actuating means for moving said switch member to open and toclosed circuit position comprising a main driving lever, a floatinglever pivotally connected to said switch member and means connectingsaid driving lever to said floating lever for multiplying the travel andspeed of operation of said switch member over that of said main drivinglever, said unitary contact assemblage in-' cluding said arcingcontacts, said operating member, said auxiliary contact, said switchmember and said actuating mechanism being removably mounted in saidcasing through one end thereof.

10. A circuit breaker for high voltage power circuits comprising, asupporting means, a plurality of vertically arranged hollow columnsmounted in spaced relation on said supporting means, a stack ofinterconnected circuit interrupting units disposed within the upperportion of each column, means for connecting all of the units in seriescircuit relationship, an operating rod extending within andlongitudinally of each column for actuating the interrupting unitstherein to open and closed positions, a common actuating means carriedby said supporting means and operatively coupled to the lower ends ofsaid operating rods for simultaneously actuating said rods to open andto close the circuit through the breaker, said columns serving toinsulate the circuit through the breaker from said support and ground,and an insulating are extinguishing liquid in each column.

11. A circuit breaker for high voltage power circuits comprising, asupporting means, a pair of vertically arranged hollow columns ofinsulating material mounted in spaced relation on said supporting means,a unitary contact assemblage disposed in the upper portion of eachcolumn including a plurality of pairs of separable main contacts and apair of auxiliary separable disconnecting contacts arranged in tandemand connected in series, and a switch member movable to open and toclosed-circuit position operable during a circuit opening operation tofirst simultaneously open all of said pairs of main contacts to open thecircuit and to subsequently open said auxiliary contacts a suflicientdistance to introduce a gap capable of withstanding high voltages andoperable during a circuit closing operation to close the pairs ofcontacts in reverse order, means connecting all of the pairs of contactsin series circuit, operating means for simultaneously moving said switchmembers to open or to closed circuit position, and an insulating arcextinguishing liquid in each column.

12. A circuit breaker for high voltage power circuits comprising asupporting means, a pair of vertically arranged hollow columns ofinsulating material mounted in spaced relation on said supporting means,a stack of series connected circuit making and breaking units disposedin the upper portion of each column, a terminal carried by each columnadjacent the base of the stack of interrupting units electricallyconnected to the lowermost unit thereof, a series connector bridging thetops of the two columns for connecting the interrupting units of eachstack in series circuit, common operating means for simultaneouslyactuating the interrupting units to open and to close the circuitthrough the breaker, the arrangement of the series connector at the topof the columns serving to more nearly equalize the voltage distributionbetween the interrupting units.

13. A circuit breaker for high'voltage power circuits comprising, asupporting means, a pair of vertically arranged hollow columns ofinsulating material mounted in spaced relation on said supporting means,a unitary contact assemblage disposed in the upper portion of eachcolumn including a. plurality of pairs of separable main contacts and apair of auxiliary separable disconnecting contacts arranged in tandemand connected in series, a switch member movable to open and toclosed-circuit position operable during a circuit opening operation tofirst simultaneously open all of said pairs of main contacts to open thecircuit and to subsequently open said auxiliary contacts a sufficientdistance to introduce a gap capable of withstanding high voltages andoperable during a circuit closing operation to close the pairs ofcontacts in reverse order, means connecting all of the pairsof contactsin series circuit, operating means for simultaneously moving said switchmembers to open or to closed circuit position, an insulating arcextinguishing liquid in each column, and means for removably mountingthe unitary contact assemblages in said columns.

14. A circuit breaker for high voltage power circuits comprising asupporting means, a pair of vertically arranged hollow columns ofinsulating material mounted in spaced relation on said supporting means,a unitary contact assemblage including a stack of series connectedcircuitmaking the breaking units and actuating means therefor disposedin the upper portion of each column, means for removably mounting theassemblages'in said columns, means connecting the units in seriescircuit, commpn operating means including operating rods" connected tothe actuating means of each stack for simultaneously actuating the unitsto open and to close the circuit through the breaker, at least one ofsaid gpperatlng rods extending axially within one of said hollowcolumns, and an insulating are extinguishing liquid in each column.

15. A circuit breaker for high voltage power circuits comprising asupporting means, a pair of vertically disposed hollow columns ofinsulating material mounted in spaced relation on said supporting means,a unitary contact assemblage includinga stack of series connectedcircuit making and breaking units, and actuating means therefor disposedin the upper portion of each column, a terminal carried by each columnadjacent the base of the stack connected to the lowermost unit thereof,a series'connector bridging the tops of the columns including aconductor for connecting the circuit making and breaking units of thetwo stacks in series circuit, operating means including an insulatingrod extending into each column for connection with the actuating meansfor simultaneously actuating the units to open or to close the circuitthrough the breaker.

16. A circuit breaker for high voltage power circuits comprising asupporting means, a pair of vertically disposedhollow columns ofinsulating materialmounted'in spaced relation on said supporting means,a unitary contact assemblage including a stack of series connectedcircuit-making and breaking units and actuating means ried by saidsupport means and operatively conpled to the lower ends of saidinsulating rods for simultaneously actuating the units to open or toclose the circuit through the breaker.

18. A circuit breaker for high voltage power circuits comprising asupporting means, a pair of vertically disposed hollow columns ofinsulating material mounted in spaced relation on said supporting means,a unitary contact assemblage including a stack of series connectedcircuit making therefor disposed in the upper portion or eachcolumn, aterminal carried by each column adjacent the base of the stack connectedto the lowermost unit thereof, a-series connector bridging the tops ofthe columns including a conductor for connecting the circuit making andbreaking units of the two stacks in series circuit, operating meansincluding an insulating rod extending into each column for connectionwith the actuating means forsimultaneously actuating the units to openor to close the circuit through the breaker, and an insulating arcextinguishing liquid in each column.

17. A circuit breaker for high voltage power circuits comprising asupporting means, a pair of vertically disposed hollow columns ofinsulating material mounted in spaced relation on said supporting means,a unitary contact assemblage including a stack of series connectedcircuit making and breaking units and actuating means therefor disposedin the upper portion of each column, a terminal carried by each columnadjacent the base of the stack connected to the lowerand breaking unitsand actuating means therefor disposed in the upper portion of eachcolumn, a terminal carried by each column adjacent the base of the stackconnected to the lowermost unit thereof, a series connector bridging thetops of the 'cohunns including a conductor for connecting the circuitmaking and breaking units of the two stacks in series circuit,'operatingmeans including an insulating rod extending into each column forconnection with the actuating means for simultaneously actuating theunits to open or to close the circuit through the breaker, and means forremovably'mounting said contact assemblages in the upper portions ofsaid columns.

19. In a circuit breaker, a movable switch member for opening andclosing the circuit, actuating mechanism for moving the switch membertoopen and toclosed circuit position including a translatable leverpivotally connected at one end to said switch member, having its otherend free of any connection and connected intermediate its ends to saidactuating mechanism for movement thereby, and support means forming atemporary fulcrum for the free end of said translatable lever during aportion of its movement.

20. In a circuit breaker, a movable switch member for opening andclosing the circuit, alctuating mechanism for moving said switch memberto open, and to closed circuit position comprising an actuating/membermovable in an arcuate path, a translatable lever pivotally connectedintermediate its ends to said actuating member for movement thereby andhaving one end pivotally connected to said switch member, guide meansfor the opposite end of said lever, said mechanism being operable'duringa closing operation to move said lever from a position transverse to thepath of movement of said switch member -'to a position substantiallyparallel to the path of movement of said switch member to efiectmovement of the, switch member to closed circuit position.

22. In a circuit breaker, a movable switch member for opening andclosing the circuit, means mounting said switch member for movement in asubstantially straight line path to an open and to a closed'circuitposition, actuating mechanism for moving said switch member to open andto closed circuit position including a translatable lever' pivotallyconnected to said 5 mechanism for movement thereby and also pivotallyconnected to said switch member, said mechanism being operable during aclosing operation to cause movement of said lever from one position to asubstantially inverted position in which it is substantially in linewith the path of movement of said switch member.

23. In a circuit breaker, a movable switch member for opening andclosing the circuit, means mounting said switch member for movement in asubstantially straight line path, actuating mechanism for moving saidswitch member to open and to closed position comprising a translatablele'ver pivotally connected intermediate its ends to said mechanism formovement thereby and having one end pivotally connected to said switchmember, guide means engageable by the other end of said lever during aportion of its movement, said mechanism being operable during a closingoperation to cause said.

lever to translate and rotate from a position in which it makes an acuteangle with the path of movement of said switch member to a substantiallyinverted position in which it is substantially in line with said path ofmovement to efiect movement of the switch member to closed position.

24. In a circuit breaker, a movable switch member for opening andclosingthe circuit, actuating mechanism for moving the switch member to openand to close the circuit, said mechanism including a lever movable bysaid mechanism and having one point thereon pivotally connected to saidswitch member and a second point thereon free of any connection, a guidemeans w forming a temporary fulcrum for the. second point on said leverduring a portion of its movement, a movable operating member for operating said actuating mechanism, saidactuating mechanism multiplying thetra'vel'and speed of operation of said switch member over that of saidoperating member. 25. In a circuit breaker, a substantially tubularcasing of relatively small diameter, a switch member in said casingmovable in the direction of the longitudinal axis of said casing foropening and closing the circuit, actuating mechanism in said casing formoving said switch member to. open and to closed position, saidmechanism includinga translatable lever movable by said 5 mechanismhaving one point pivoted to saidswitch member and a second point free ofany connection, guide means forming a temporary fulcrum for the secondpoint on said lever during a portion of its movement, said mechanism 00being operable during a closing operation to cause said lever to fulcrumon said guide means andtranslate to a position substantially parallel tothe longitudinal axis of said casing.

26. In a circuit breaker, a movable switch 65 member for opening andclosing the circuit actuating mechanism for moving said switch mem-'berto open and to closed circuit position, including a translatablelever pivotally connected at one end to said switch member and movable70 by said mechanism, said mechanism being operable to effect.translating movement of said lever and rotation thereof through anangle greater than 90 to effect movement of the switch member. g5 27. Ina circuit breaker, a movable switch member for opening and closing thecircuit, means mounting said switch member for movement in a.substantially straight line path, actuating mechanism for moving saidswitch member to open and to closed circuit position comprising anactuating member movable in an arcuate path, a translatable leverpivotally connected in-' termediate its ends to said actuating memberfor movement thereby, and having one end pivotally connected to saidswitch member, guide means for the opposite end of said lever, saidmechanism being operable during a closing operation to move said leverfrom a position transverse to the path of movement of said switch memberto a position substantially parallel to the path of movement of saidswitch member to eifect movement of the switch member to closed circuitposition, an operating member for operating said actuating mechanism,said actuating mechanism multiplying the travel and speed of saidoperating member.

28. In a circuit breaker for high voltage power circuits, a casing, aswitch member movable to open and closed positions to open and close thecircuit through the breaker, means mounting said switch member formovement within said casing, actuating means disposed in said casing formoving said switch member to open and closed positions comprising a maindriving lever pivotally supported adjacent one end, an intermediatemultiplying lever pivotally supported adjacent one end, the free end ofsaid main lever being pivotally coupled to said intermediate leveradjacent the pivoted end thereof, and a transn -20 operation of saidswitch member over that-of column for operating said interrupting meansto open and closed positions, said actuating means including anoperating rod extending through said transformer chamber and operativelycoupled with said interrupting means, and tubular means surrounding saidoperating rod and joining the respective ends of said transformerchamber to prevent the intermingling of liquid between said chambers.

30. In a circuit interrupter, a housing comprising a pair of tubularsections of insulating material, a metallic casing disposed between saidsections, closures for the opposite ends of said sections and apartition wall within said casing dividing said housing into circuitinterrupting and transformer chambera, insulating liquid within each ofsaid chambers, circuit interrupt: ing. means including a movable contactcarrying member disposed within said circuit interrupting chamberoperating means in said casing for actuating saidcontact carrying memberto open and closed positions, an operating rod extending through saidtransformer chamber for actuating said operating means, and tubularmeans surrounding said operating rod and joining the respective ends ofsaid. transformer chamber to prevent the intermingling of liquid betweensaid chambers. JOHN B. BEACNEIIILJ

